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Amido Sulfones (amido + sulfone)
Selected AbstractsAsymmetric Synthesis of ,,,-Diaminophosphonic Acid Derivatives with a Catalytic Enantioselective Mannich ReactionADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2009Robert Djiokeng Momo Abstract Optically active ,,,-diaminophosphonic acid derivatives were obtained from the catalytic enantioselective Mannich reaction of phosphoglycine Schiff bases with N -Boc-imines, generated in situ from ,-amido sulfones. [source] Doubly Stereocontrolled Asymmetric Aza-Henry Reaction with in situ Generation of N -Boc-Imines Catalyzed by Novel Rosin-Derived Amine Thiourea CatalystsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2009Xianxing Jiang Abstract The doubly stereocontrolled organocatalytic aza-Henry reaction of nitroalkanes to N -Boc-imines generated in situ from a variety of substituted ,-amido sulfones was investigated for the first time, in general, affording the corresponding products with high to excellent yields (up to 93% yield) and enantioselectivities (up to 98% ee), and satisfactory diastereoselectivies (anti/syn up to 98:2). Furthermore, these organocatalysts based on rosin have been proved to be the very effective promoters for this catalytic asymmetric process along side the Cinchona alkaloid-derived catalysts. [source] Use of the Chiral Pool , Practical Asymmetric Organocatalytic Strecker Reaction with QuinineADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 7-8 2009Rüdiger Reingruber Abstract An efficient, organocatalytic enantioselective synthesis of N -arylsulfonyl ,-amino nitriles from the corresponding ,-amido sulfones has been developed. This quinine-catalyzed Strecker reaction provides the corresponding cyanated products in good yields and enantioselectivities. [source] Organocatalytic Asymmetric Mannich Reactions with N -Boc and N -Cbz Protected ,-Amido Sulfones (Boc: tert -Butoxycarbonyl, Cbz: Benzyloxycarbonyl)CHEMISTRY - A EUROPEAN JOURNAL, Issue 29 2007Olindo Marianacci Abstract Different malonates and ,-ketoesters can react with N - tert -butoxycarbonyl- (N -Boc) and N -benzyloxycarbonyl- (N -Cbz) protected ,-amido sulfones in an organocatalytic asymmetric Mannich-type reaction. The reaction makes use of a simple and easily obtained phase-transfer catalyst and proceeds under very mild and user-friendly conditions. The optimised protocol avoids the preparation and the isolation of the relatively unstable N -Boc and N- Cbz imines that are generated in situ from the bench-stable ,-amido sulfones. The corresponding Mannich bases are generally obtained in good yields and enantioselectivities, and can be readily transformed into key compounds, such as optically active ,3 -amino acids in one easy step. Enantioenriched N -Boc and N -Cbz protected ,-amino acids that are suitable for peptide synthesis are also available from the Mannich adducts through simple manipulations. Control experiments showed the dual role of the enolate,catalyst ion pair in this reaction, as well as the crucial role of the presence of water to achieve high enantioselectivities. [source] | ||||||||||